1. Field of the Invention
The present invention relates to an image processing apparatus which digitally processes an input image and performs various image processing operations of the digital image data.
2. Related Background Art
In recent years, digital color copying machines are becoming popular. In a copying machine of this type, a color original is color-separated and read in units of pixels, read image data are digitally processed, and obtained digital signals are output to a color printer, thereby obtaining a digital color hard copy. Since an apparatus of this type can digitally process image data, various image processes are available, and an application range in the field of color copy tends to be widened. In the image process modes, an output position of an image is shifted (FIG. 72A), a desired image area is extracted (FIG. 72B), only a color in a desired area is converted (FIG. 72C), a character or image stored in a memory is fitted in a reflective original (FIG. 72D), and so on.
Requirements for outputting images and characters to be worthy of their names are increasingly demanded for a color reflective original. In order to meet these requirements, character and image portions are separated by image area separation, so that high-resolution processing is performed for the character portion, in particular, processing for printing black characters in single black color is performed, and multigradation processing is performed for the image portion. This technique is disclosed in a patent and an application by the same assignee as the present invention (U.S. Pat. No. 4,958,219 and U.S. patent application Ser. No. 327,098).
However, in the prior art, the following drawbacks are posed.
(1) When a binary color character image is synthesized with a reflective original,
[1] for example, when image area judgement of an image on a reflective original to identify a portion other than a character area, and processing for changing a printing condition, e.g., a resolution, is performed based on the judged portion, the changed printing condition influences a character portion of a binary character image to be synthesized; and
[2] even when the printing condition is left unchanged on a character portion to be synthesized, no high-resolution processing is performed, and a high-resolution character image cannot be obtained.
(2) When a color image is synthesized with a reflective original,
[1] when the same processing as in [1] in item (1) is performed for a reflective original, its printing condition influences a synthesized image portion; and
[2] even when the printing condition is left unchanged on a synthesized color image portion, no multigradation processing is performed, and a multigradation color image cannot be obtained.
On the other hand, upon systemization of an apparatus and expansion of edit functions, when a full-color image input from an external apparatus is synthesized with a predetermined area in an original, as shown in FIG. 76 (when an image A is fitted in an area B), the area B is originally an area where characters are printed, i.e., a character area, as shown in FIG. 76. In this case, when characters are black ones, if control for printing characters in single black color is enabled, noise components are generated in the fitted image A in the form of characters.
In conventional image processing for performing image area judgement and changing a printing condition (e.g., resolution) on the basis of an output signal of image area judgement, when a process and edit operation of an image, e.g,. paint processing of a specific area is performed, the changed printing condition influences a painted portion, resulting in a problem of image area judgement.
Since a conventional method does not consider the relationship between image area judgement and image process and edit operations, when an image zoom or shift operation is performed, such an operation cannot be performed in correspondence with an image area judgement result. That is, a processed or edited image cannot be appropriately processed using the image area judgement result.